I am also having this same problem. I ran the java file and it found my PS3 as an "unknown device", and none of the engines loaded so I couldn't watch any videos. So, I quit the PMS. I then restarted it as the .exe file and it worked. I don't know if this action "kicked it into gear", though.

I was having all sorts of errors when trying to update to the current PMS version. Through restarting, uninstalling, re-downloading, etc. I eventually got the latest PMS to completely install properly.

I believe this issue is java related. I completely uninstalled all versions of java and reinstalled just the latest version.

Still this problem persisted. But I ran the pms.jar, it failed to load all my engines, I quit, then restarted the pms regularly and it worked fine.

After using it today, I quit the PMS and re-started it and got the same problem. And so this time I simply ran the pms.jar and THIS time it ran fine with all appropriate engines running.

This issue seems to have variations of behavior. For now I just created a desktop icon for the PMS.JAR file and am running it through that.

3. wifi connection through Apple Airport Extreme, using a netgear external wifi card on my PC (I have to admit this thing has been giving me problems lately, dropping connection; and I often have to pull it out and plug it back in to get it to work)